Rapid Growth of Monolayer MoSe Films for Large-Area Electronics.

The large-scale growth of semiconducting thin films on insulating substrates enables batch fabrication of atomically thin electronic and optoelectronic devices and circuits without film transfer. Here an efficient method to achieve rapid growth of large-area monolayer MoSe films based on spin coating of Mo precursor and assisted by NaCl is reported. Uniform monolayer MoSe films up to a few inches in size are obtained within a short growth time of 5 min.

Large area few-layer TMD film growths and their applications.

Research on 2D materials is one of the core themes of modern condensed matter physics. Prompted by the experimental isolation of graphene, much attention has been given to the unique optical, electronic, and structural properties of these materials. In the past few years, semiconducting transition metal dichalcogenides (TMDs) have attracted increasing interest due to properties such as direct band gaps and intrinsically broken inversion symmetry.

Atomic-scale patterning in two-dimensional van der Waals superlattices.

Two-dimensional (2D) van der Waals superlattices comprised of two stacked monolayer materials have attracted significant interest as platforms for novel optoelectronic and structural behavior. Although studies are focused on superlattice fabrication, less effort has been given to the nanoscale patterning and structural modification of these systems. In this report, we demonstrate the localized layer-by-layer thinning and formation of nanopores/defects in 2D superlattices, such as stacked MoS-WS van der Waals heterostructures and chemical vapor deposited bilayer WSe, using aberration-corrected scanning transmission electron microscopy (STEM).

Controlled Growth of Large-Area Bilayer Tungsten Diselenides with Lateral P-N Junctions.

Bilayer two-dimensional (2D) van der Waals (vdW) materials are attracting increasing attention due to their predicted high quality electronic and optical properties. Here, we demonstrate dense, selective growth of WSe bilayer flakes by chemical vapor deposition with the use of a 1:10 molar mixture of sodium cholate and sodium chloride as the growth promoter to control the local diffusion of W-containing species. A large fraction of the bilayer WSe flakes showed a 0 (AB) and 60° (AA') twist between the two layers, whereas Moiré 15 and 30° twist angles were also observed.